So I've been building an app using the Giant Bomb Api which heavily relies on release dates of games to function correctly. And I've regularly noticed that while the wiki says an expected release date like "2019", The API will sometimes show an actual release date in the "original_release_date" column, while not having entries in the "expected_release_year", "expected_release_day" etc. columns. The release date given in the API is thus usually wrong.
I've just noticed this with Mario & Sonic at the 2020 Tokyo Olympics as well with Persona 5 Scramble. I've attached screenshots of the mismatch in the data. One of them is from the wiki page of P5S, the other is of the API.